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Those are for the Arena Payout changes:
These changes will go into effect on 12/08 with the first Grand Arena Championship beginning 12/13. If you’re level 85, keep an eye on your inbox. We’re doing a one-time grant of 500 Crystals as players transition from Squad Arena payouts to Grand Arenas payouts.
Source: https://forums.galaxy-of-heroes.starwars.ea.com/discussion/252003/title-update-12-08-2021